1. Field of the Invention
This disclosure generally relates to medical devices. More particularly, the disclosure relates to a device for delivering and deploying a prosthesis and a method of delivering and deploying the prosthesis.
2. Description of the Related Art
A prosthesis, such as a self-expanding stent, is typically introduced into a patient body using a delivery device that includes an outer sheath coaxially disposed and slidable over an inner catheter. The prosthesis may be disposed at the distal end of the device between the inner catheter and the outer sheath and held in a compressed configuration by the outer sheath. The inner catheter and the outer sheath move coaxially with respect to each other.
If the prosthesis is a self-expanding stent, for example, it may be deployed by pulling back the outer sheath in a proximal direction relative to the inner catheter until the stent is exposed. The self-expanding stent expands from the stent distal end to the stent proximal end as the sheath is proximally withdrawn.
The total length of the medical device may be dictated not only by the length of each component thereof, but also by a length by which the sheath must be withdrawn in order to expose the stent. For example, if the stent is about 100 mm long and completely covered by the sheath, in order to deploy (uncover) the stent, the sheath must be withdrawn in the proximal direction about 100 mm. Thus, the medical device will typically need to be an extra 100 mm long since the sheath will need to be withdrawn by this length to deploy the stent.
Longer medical device lengths pose numerous problems to a physician or operator using the medical device. In general, the longer the medical device, the more difficult to handle and control. Thus, it is advantageous to keep the medical device to a minimal length.